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Dive into the research topics where Koichi Tsutahara is active.

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Featured researches published by Koichi Tsutahara.


Transplantation | 2012

Blocking of CCR5 and CXCR3 suppresses the infiltration of macrophages in acute renal allograft rejection.

Yoichi Kakuta; Masayoshi Okumi; Shuji Miyagawa; Koichi Tsutahara; Toyofumi Abe; Koji Yazawa; Katsuyoshi Matsunami; Hideaki Otsuka; Shiro Takahara; Norio Nonomura

Background. The chemokine receptors CCR5 and CXCR3 are expressed by T cells and macrophages. We examined effects of a CCR5/CXCR3 antagonist (TAK), with a particular focus on the role of macrophages, in a rat kidney transplant model. Methods. Dark Agouti rat kidneys were transplanted into Lewis rats. The recipients were treated daily with a 10 mg/kg TAK on posttransplant days 0 to 14 and/or 2 mg/kg of cyclosporine A (CsA) on days 0 to 5. Graft survival, histological changes, and the expression of chemokines and chemokine receptors on T cells and macrophages were studied. Results. Treatment with TAK alone suppressed CD4+T cell infiltration and slightly prolonged graft survival. The expressions of both CCR5 and CXCR3, and activated macrophage-associated cytokines and chemokines, were significantly increased on macrophages that had been separated from rejecting kidneys, compared with those from spleens. However, these upregulations were decreased in macrophages from kidneys that had been treated with TAK. Immunohistochemistry also showed that macrophages infiltrating tubules of rejecting kidney expressed both receptors. In the CsA alone group, macrophages were the dominant infiltrating cells, and all allografts were rejected within 10 days. A combined therapy involving CsA and TAK resulted in decreased macrophage infiltration, and graft survival was substantially prolonged. The levels of activated macrophage-associated cytokines and chemokines were also decreased. Conclusion. The dual blocking of CCR5/CXCR3 can be useful in decreasing rejection, with or without CsA. This mechanism acts, not only to block T-cell recruitment to a kidney graft but to suppress the infiltration of macrophages as well.


Transplantation | 2012

Hydrogen-rich University of Wisconsin solution attenuates renal cold ischemia-reperfusion injury.

Toyofumi Abe; Xiao-Kang Li; Koji Yazawa; Naoyuki Hatayama; Lin Xie; Bunpei Sato; Yoichi Kakuta; Koichi Tsutahara; Masayoshi Okumi; Hidetoshi Tsuda; Jun-ya Kaimori; Yoshitaka Isaka; Michiya Natori; Shiro Takahara; Norio Nonomura

Background Renal ischemia-reperfusion (I/R) injury is unavoidable in kidney transplantation and frequently influences both short- and long-term allograft survival rates. One of the major events in I/R injury is the generation of cytotoxic oxygen radicals. Recently, hydrogen gas has been reported to display antioxidant properties and protective effects against organ dysfunction induced by various I/R injuries. We investigated whether hydrogen-rich University of Wisconsin (HRUW) solution attenuates renal cold I/R injury. Methods We prepared HRUW solution by a novel method involving immersion of centrifuge tubes containing UW solution into hydrogen-saturated water. Hydrogen readily permeates through the centrifuge tubes, and thus, the hydrogen concentration of the UW solution gradually increases in a time-dependent manner. Syngeneic rat kidney transplantation was performed, and the animals were divided into three groups: recipients with nonpreserved grafts (control group), recipients with grafts preserved in UW solution for 24 to 48 hr (UW group), and recipients with grafts preserved in HRUW solution for 24 to 48 hr (HRUW group). Results In the early phases, HRUW solution decreased oxidative stress, tubular apoptosis, and interstitial macrophage infiltration in the kidney grafts. Consequently, HRUW solution improved renal function and prolonged recipient survival rate compared with simple cold storage using UW solution. Histopathologically, HRUW treatment alleviated tubular injury and suppressed development of interstitial fibrosis. Conclusions HRUW solution improved graft function and prolonged graft survival compared with simple cold storage using UW solution by protecting tubular epithelial cells from inflammation and apoptosis. Our new method of organ preservation is a groundbreaking, safe, and simple strategy that may be applied in the clinical setting.


Transplant International | 2011

Epigallocatechin-3-gallate protects kidneys from ischemia reperfusion injury by HO-1 upregulation and inhibition of macrophage infiltration

Yoichi Kakuta; Masayoshi Okumi; Yoshitaka Isaka; Koichi Tsutahara; Toyofumi Abe; Koji Yazawa; Naotsugu Ichimaru; Kazuaki Matsumura; Suong-Hyu Hyon; Shiro Takahara; Norio Nonomura

Epigallocatechin‐3‐gallate (EGCG) shows diverse chemical and biological activities. We investigated the effects of EGCG in a rat renal ischemia reperfusion (I/R) injury model. Sprague–Dawley rats received intraperitoneal injection of 50 mg/kg EGCG 48 h, 24 h, and 30 min prior to I/R injury. The animals were subjected to left renal occlusion for 45 min. EGCG treatment suppressed the peak in serum creatinine. EGCG‐treated kidneys showed significantly less tubular damage and a decreased number of apoptotic cells. The I/R‐induced elevation in the renal MDA level was significantly decreased in the EGCG group. Reverse‐transcriptase polymerase chain reaction showed that EGCG significantly decreased the expression of MHC class II, TLR2, TLR4, MCP‐1, IL‐18, TGF‐β1, procollagen Ia1, TIMP‐1, and Kim‐1. ED‐1 staining showed reduced macrophage infiltration and α‐SMA staining revealed less interstitial expression. Heme oxygenase‐1 (HO‐1) expression in I/R kidneys was upregulated in the EGCG group based on the results of both RT‐PCR and Western blotting analysis. Blockade of HO‐1 gene induction by SnPP increased renal tubular damage and macrophage infiltration. These findings suggest that EGCG protects the kidneys against I/R injury by reducing macrophage infiltration and decreasing renal fibrosis. These beneficial effects may be mediated, in part, by augmentation of the HO‐1 gene.


Transplantation | 2014

Adipose tissue-derived stem cells suppress acute cellular rejection by TSG-6 and CD44 interaction in rat kidney transplantation.

Taigo Kato; Masayoshi Okumi; Masahiro Tanemura; Koji Yazawa; Yoichi Kakuta; Kazuaki Yamanaka; Koichi Tsutahara; Yuichiro Doki; Masaki Mori; Shiro Takahara; Norio Nonomura

Background In addition to its abundance and easy accessibility, adipose tissue yields more potent immunoregulatory stem cells (adipose tissue-derived stem cells, ADSCs) than does bone marrow. However, the beneficial effects of ADSCs on alloreactivity are scarcely known. This study evaluated the beneficial effects of ADSCs in rat kidney transplantation and analyzed the underlying molecular mechanism. Methods Dark Agouti rat kidneys were transplanted into Lewis rats. Autologous ADSCs (2×106) were injected through the left renal artery of the donors before the nephrectomy (ADSCs group). Graft survival, histologic changes, and the expression of several cytokines and proteins were assessed. In an in vitro experiment, the immunosuppressive capacity of ADSCs was tested in a mixed lymphocyte reaction. Results Histologic findings of the ADSCs group revealed a reduced rejection grade, whereas the number of infiltrated CD4+/CD8+ T cells was also significantly decreased as compared to the control. Relative to these findings, injection of ADSCs led to a significantly prolonged mean graft survival compared with the control. In vitro, autologous ADSCs dose-dependently suppressed alloreactive lymphocytes. Moreover, ADSCs increased the level of tumor necrosis factor-inducible gene 6 protein (TSG-6) in mixed lymphocyte reaction, which has an anti-inflammatory capacity. Recombinant TSG-6 markedly suppressed alloreactive T cells through downregulating CD44, which may lead to the suppression of T-cell activation and infiltration into allografts. Conclusion Our findings clearly showed that ADSCs attenuated acute rejection by secreting TSG-6 as well as through direct cell interaction. These findings contribute to the clinical application of these cells in solid organ transplantation.


Nephrology Dialysis Transplantation | 2012

The blocking of CXCR3 and CCR5 suppresses the infiltration of T lymphocytes in rat renal ischemia reperfusion

Koichi Tsutahara; Masayoshi Okumi; Yoichi Kakuta; Toyofumi Abe; Koji Yazawa; Shuji Miyagawa; Katsuyoshi Matsunami; Hidetoshi Otsuka; Jun-ya Kaimori; Shiro Takahara; Norio Nonomura

BACKGROUND Recent studies have identified T cells and natural killer T (NKT) cells as important mediators in renal ischemia-reperfusion (I/R) injury. The recruitment of these cells is induced by chemotaxis factors. We investigated the effects of blocking CXCR3 and CCR5 by an antagonist (TAK) using a rat renal I/R injury model. METHODS The Sprague-Dawley rats were either subjected to sham operation or left renal occlusion for 45 min followed by reperfusion and contralateral nephrectomy. The control or TAK groups were, respectively, injected phosphate-buffered saline or TAK at 30 min prior to clamp. Serum creatinine, tubular injury, chemokines expression and infiltrating cells were assessed. RESULTS TAK treatment significantly suppressed the elevation in serum creatinine (sham 0.40 ± 0.05 mg/dL, control 2.86 ± 0.67 mg/dL, TAK 1.60 ± 0.73 mg/dL) and resulted in a lower tubular injury score compared with the control group (sham 0, control 4.8 ± 0.3, TAK 3.3 ± 1). The mRNA expression of chemokines that bind to CXCR3 and CCR5 in the post-ischemic kidneys was elevated at 1 h after reperfusion in each group. Moreover, the infiltration of CD4+ T cells and CD8+ NKT cells in the control group increased compared with the sham group and TAK injection significantly suppressed the number of CD4+ T cells (sham 13.5 ± 3.5 × 10(4) cells, control 28.9 ± 15.4 × 10(4) cells, TAK 11.8 ± 3.5 × 10(4) cells) and the number of CD8+ NKT cells (sham 11.7 ± 5.4 × 10(4) cells, control 30.1 ± 8.6 × 10(4) cells, TAK 11.8 ± 2.9 × 10(4) cells). CONCLUSIONS These findings suggest that the blocking of CXCR3 and CCR5 suppress the infiltration of T cells and NKT cells and have a protective effect on kidneys that are injured by I/R.


Laboratory Investigation | 2017

High-pressure carbon monoxide preserves rat kidney grafts from apoptosis and inflammation

Toyofumi Abe; Koji Yazawa; Masayuki Fujino; Ryoichi Imamura; Naoyuki Hatayama; Yoichi Kakuta; Koichi Tsutahara; Masayoshi Okumi; Naotsugu Ichimaru; Jun-ya Kaimori; Yoshitaka Isaka; Kunihiro Seki; Shiro Takahara; Xiao-Kang Li; Norio Nonomura

Renal ischemia–reperfusion (I/R) injury is unavoidable in kidney transplantation (KTx) and frequently influences both short- and long-term allograft survival. Carbon monoxide (CO) has attracted attention as a medical gas with anti-inflammatory and anti-apoptotic effects. We investigated a new strategy for organ preservation using ex vivo application of high-pressure CO in an experimental rat KTx model. We preserved kidney grafts using a high-pressure chamber filled with mixed gases composed of CO and O2. We found that cold I/R injury resulted in progressive deterioration of renal graft function in University of Wisconsin solution, whereas CO significantly improved renal function. We confirmed that CO decreased oxidative stress and mRNA expression of proinflammatory cytokines and inhibited tubular apoptosis in the early phases. Western blot analysis demonstrated that CO increased phosphatidylinositol-3 kinase and phosphorylation of Akt and p38 mitogen-activated protein kinase. Furthermore, CO significantly alleviated tubular injury scores and suppressed the development of interstitial fibrosis at 100 days after KTx. Thus, high-pressure mixed CO and O2 gases successfully preserved rat kidney grafts for 24 h by protecting tubular epithelial cells from apoptosis and inhibiting inflammation.


International Journal of Urology | 2016

Clinical analysis of severe psychiatric disorders in patients with testicular cancer: A single-center experience.

Nozomu Kishimoto; Tetsuya Takao; Koichi Tsutahara; Go Tanigawa; Seiji Yamaguchi

1 Matsuzaki K, Fujita K, Ujike T, Uemura M, Nonomura N, Miyagawa Y. Is it necessary to carry out intraoperative retrograde upper urinary tract cytology examination in bladder cancer patients with normal upper urinary tract appearance and suspicious or positive voided urine cytology? Int. J. Urol. 2016; 23: 623–4. 2 Otto W, Shariat SF, Fritsche HM et al. Concomitant carcinoma in situ as an independent prognostic parameter for recurrence and survival in upper tract urothelial carcinoma: a multicenter analysis of 772 patients. World J. Urol. 2011; 29: 487–94. 3 Wolf H, Melsen F, Pedersen SE, Nielsen KT. Natural history of carcinoma in situ of the urinary bladder. Scand. J. Urol. Nephrol. Suppl. 1994; 157: 147– 51. 4 Kojima Y, Tozawa K, Kawai N, Sasaki S, Hayashi Y, Kohri K. Long-term outcome of upper urinary tract carcinoma in situ: effectiveness of nephroureterectomy versus bacillus Calmette-Gu erin therapy. Int. J. Urol. 2006; 13: 340–4. 5 Inamoto T, Azuma H. Editorial Comment to Is it necessary to carry out intraoperative retrograde upper urinary tract cytology examination in bladder cancer patients with normal upper urinary tract appearance and suspicious or positive voided urine cytology? Int. J. Urol. 2016; 23: 625.


Cuaj-canadian Urological Association Journal | 2015

A rare case of spontaneous necrosis of primary renal cell carcinoma

Kyosuke Matsuzaki; Ryoichi Imamura; Toshichika Iwanishi; Masahiro Nakagawa; Go Tanigawa; Koichi Tsutahara; Kohki Shimazu; Hiroaki Fushimi; Toyonori Tsuzuki; Seiji Yamaguchi

A 42-year-old woman was referred to our hospital with a chief complaint of asymptomatic gross hematuria. Computed tomography revealed a 4-cm tumour in the left kidney and radical nephrectomy was performed. Microscopically, the tumour was completely necrotic and consisted of nests of cells with abundant cytoplasm and large nuclei. Immunohistochemical analysis indicated complete infarction of the chromophobe renal cell carcinoma. Two years after surgery, the patient remained recurrence-free.


The Japanese Journal of Urology | 2017

A CASE OF PELVIC FRACTURE URETHRAL INJURY RECONSTRUCTED BY DEFERRED URETHROPLASTY

Sohei Kuribayashi; Takuya Okusa; Go Tanigawa; Gaku Yamamichi; Masataka Kawamura; Kosuke Nakano; Nozomu Kishimoto; Koichi Tsutahara; Tetsuya Takao; Seiji Yamaguchi

We report a case of pelvic fracture urethral injury reconstructed by anastomotic urethroplasty. A 24-year-old male was referred to our hospital because of pelvic trauma accompanying ischial fracture. Retrograde urethrography showed urethral disruption and suprapubic catheter was inserted. One week later, we underwent endoscopic realignment. Three months later, we removed the Foley balloon catheter after we had checked that there was no stricture by the voiding cystourethrogram. However, 5 days after that, he came to our hospital because of urinary retention. Cystoscopy detected urinary stricture between bulbar and membranous urethra. We decided to do deferred urethroplasty. Five months after that we performed anastomotic urethroplasty. He was discharged 31 days after the operation. No stricture has been detected for 7 months postoperatively.


International Braz J Urol | 2016

Impact of prior abdominal surgery on the outcomes after robotic - assisted laparoscopic radical prostatectomy: single center experience.

Nozomu Kishimoto; Tetsuya Takao; Gaku Yamamichi; Takuya Okusa; Ayumu Taniguchi; Koichi Tsutahara; Go Tanigawa; Seiji Yamaguchi

ABSTRACT Purpose: To evaluate the influence of prior abdominal surgery on the outcomes after robotic-assisted laparoscopic radical prostatectomy (RALP). Materials and Methods: We retrospectively analyzed patients with prostate cancer who underwent RALP between June 2012 and February 2015 at our institution. Patients with prior abdominal surgery were compared with those without prior surgery while considering the mean total operating, console, and port-insertion times; mean estimated blood loss; positive surgical margin rate; mean duration of catheterization; and rate of complications. Results: A total of 203 patients who underwent RALP during the study period were included in this study. In all, 65 patients (32%) had a prior history of abdominal surgery, whereas 138 patients (68%) had no prior history. The total operating, console, and port-insertion times were 328 and 308 (P=0.06), 252 and 242 (P=0.28), and 22 and 17 minutes (P=0.01), respectively, for patients with prior and no prior surgery. The estimated blood losses, positive surgical margin rates, mean durations of catheterization, and complication rates were 197 and 170 mL (P=0.29), 26.2% and 20.2% (P=0.32), 7.1 and 6.8 days (P=0.74), and 12.3% and 8.7% (P=0.42), respectively. Furthermore, whether prior abdominal surgery was performed above or below the umbilicus or whether single or multiple surgeries were performed did not further affect the perioperative outcomes. Conclusions: Our results suggest that RALP can be performed safely in patients with prior abdominal surgery, without increasing the risk of complications.

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